Synoptic, mesoscale, and microscale influences on near surface radio frequency clear air propagation in the coastal atmosphere

Near surface clear air radio frequency (RF) propagation in the coastal area is the result of air/sea/land interactions influenced primarily by the characteristics of the surface of the land and sea. Synoptic influences by large scale (approximately 300 km) meteorological features, such as cold fronts and high-pressure ridges, control wind direction and sources of water vapor. Mesoscale meteorological influences (approximately 50 km), such as sea breeze and convective precipitation, may rapidly change the propagation environment. Microscale meteorological structures (approximately 1 km), such as the atmospheric boundary layer, react to the larger synoptic and mesoscale features to create spatiotemporal refractivity fields. The paper presents the results of a three-year research effort that identifies the larger scale meteorological processes that impose non-standard propagation structures in the coastal marine atmospheric boundary layer. Highly resolved propagation and thermodynamic data from Wallops Island, Virginia, the California coast, and the Persian Gulf are combined with archived meteorological data in order to relate anomalous clear air propagation to universal weather map features.